[Federal Register: April 25, 2006 (Volume 71, Number 79)]
[Proposed Rules]
[Page 23886-23893]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr25ap06-17]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants: 90-Day Finding on
a Petition To List the Siskiyou Mountains Salamander and Scott Bar
Salamander as Threatened or Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 90-day petition finding.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to list the Siskiyou Mountains salamander
(Plethodon stormi) and Scott Bar salamander (Plethodon asupak) as
threatened or endangered, under the Endangered Species Act (Act) of
1973, as amended (16 U.S.C. 1531 et seq.). We find that the petition
and additional information in our files do not present substantial
scientific or commercial information indicating that listing these
species may be warranted. We will not be initiating a status review in
response to this petition. We ask the public to submit to us any new
information that becomes available concerning the status of, or threats
to these species.
DATES: The finding announced in this document was made on April 17,
2006. You may submit new information concerning these species for our
consideration at any time.
ADDRESSES: The complete file for this finding is available for public
inspection, by appointment, during normal business hours at the Yreka
Fish and Wildlife Office, U.S. Fish and Wildlife Service, 1829 S.
Oregon Street, Yreka, California 96097. Submit new information,
materials, comments, or questions concerning these species to us at the
address above.
FOR FURTHER INFORMATION CONTACT: Phil Detrich, Field Supervisor, Yreka
Fish and Wildlife Office (see ADDRESSES), or at (530) 842-5763.
SUPPLEMENTARY INFORMATION:
Background
Section 4(b)(3)(A) of the Act requires that the Service make a
finding on whether a petition to list, delist, or reclassify a species
presents substantial scientific or commercial information indicating
that the petitioned action may be warranted. This finding is based on
information contained in the petition and information otherwise
available in our files at the time we make the finding. To the maximum
extent practicable, we are to make this finding within 90 days of our
receipt of the petition, and publish our notice of the finding promptly
in the Federal Register.
In making this finding, we relied on information provided by the
petitioners and otherwise available in our files at the time of the
petition review. We also had access to a Geographic Information System
database of all known Siskiyou Mountain salamander and Scott Bar
salamander sites, based on data obtained from researchers, the State of
California, the United States Forest Service, and private land
managers. We evaluated this information in accordance with 50 CFR
424.14(b). The process of making a 90-day finding under section
4(b)(3)(A) of the Act and section 424.14(b) of our regulations is based
on a determination of whether the information in the petition meets the
``substantial scientific or commercial information'' threshold.
Our standard for substantial scientific or commercial information
within the Code of Federal Regulations (CFR) with regard to a 90-day
petition finding is ``that amount of information that would lead a
reasonable person to believe that the measure proposed in the petition
may be warranted'' (50 CFR 424.14(b)). If we find that substantial
scientific or commercial information was presented, we are required to
promptly commence a status review of the species.
On June 18, 2004, we received a petition dated June 16, 2004 from
the Center for Biological Diversity, Klamath-Siskiyou Wildlands Center,
and Noah Greenwald, to list the Siskiyou Mountains salamander
(Plethodon stormi) as a threatened or endangered species on behalf of
themselves and five other organizations. Since the time of the
petition, Mead et al. (2005) recognized the Scott Bar salamander
(Plethodon asupak) as a species separate from the Siskiyou Mountains
salamander. In their petition, the petitioners requested that the Scott
Bar salamander also be considered for listing if the Siskiyou Mountains
salamander and the Scott Bar salamander were determined to be separate
species. Given the recent recognition of these as separate taxa, we
acknowledge that some may question the validity of these species.
However, elucidating these taxonomic questions is not the purpose of
this finding. The purpose of this finding is to determine whether or
not the petition presented substantial information regarding the status
of these species within the context of the ESA. The petitioners also
requested designation of critical habitat for these species concurrent
with their listing. The petition clearly identified itself as such and
included the requisite identification information for the petitioners,
as required in 50 CFR 424.14(a). In a July 19, 2004 letter to the
petitioners, we responded that we reviewed the petition for both
species and determined that an emergency listing was not warranted, and
that because of inadequate funds for listing and critical habitat
designation, we would not be able to otherwise address the petition to
list the Siskiyou Mountains salamander and Scott Bar salamander at that
time.
On June 23, 2005, we received a 60-day notice of intent to sue and
on August 23, 2005, the Center for Biological Diversity and four other
groups filed a Complaint for Declaratory and Injunctive Relief in
Federal District Court for the District of Oregon (Center for
Biological Diversity, et al. v. Norton et al., No. 3:05-CV-1311-BR),
challenging our failure to issue a 90-day finding on the petition to
list the Siskiyou Mountains salamander and Scott Bar salamander. On
December 28, 2005, we reached an agreement with the plaintiffs to
complete the 90-day finding by April 15, 2006, and if substantial, to
complete the 12-month finding by January 15, 2007.
Species Information
For the purpose of this finding, the Service is evaluating the
Siskiyou Mountains salamander and Scott Bar salamander separately.
However, we recognize that all research on the ecology of these species
was conducted prior to Mead et al.'s (2005) recognition of the Scott
Bar salamander as a separate species. To date, information specific to
the Scott Bar salamander is limited to its distribution and range. Both
species are members of the Family Plethodontidae, the lungless
salamanders, and as such their survival is dependent upon similar
ecological requirements. The geographic ranges of the Siskiyou
Mountains salamander and Scott Bar salamander are contiguous, occur
over a relatively
[[Page 23887]]
small area (approximately 405,000 acres (164,000 ha)), and have similar
environmental conditions. Additionally, information in our files
suggests that habitat associations of these species are generally the
same, although a rigorous study comparing their habitat requirements
has not been conducted. The most significant difference between these
species is their range; the range of the Siskiyou Mountains salamander
is approximately five times larger than that of the Scott Bar
salamander. Therefore, for the purpose of this finding, the Service
applied the current literature describing the biological
characteristics and ecology of the Siskiyou Mountains salamander to
both species. Further, we recognized both entities as separate species
consistent with the petition under review while acknowledging that
taxonomic questions may exists. It is not the purpose of this finding
to resolve such questions.
Description and Taxonomy
Like others in the genus Plethodontidae, the Siskiyou Mountains
salamander and Scott Bar salamander are completely terrestrial, medium-
sized, slender-bodied salamanders with short limbs and a dorsal stripe.
Both species are found in or near talus (loose surface rock) and
fissured rock outcrops where moisture and humidity are high enough to
allow respiration through their skin (Nussbaum et al. 1983). Both
species are endemic to the Klamath-Siskiyou Mountains of southern
Oregon and northern California.
The Siskiyou Mountains salamander was described in 1965 (Highton
and Brame 1965) and is characterized by a modal number of 17 costal
grooves (vertical creases along the side of the body) and 4 to 5.5
intercostal folds (folds of skin between the costal grooves) between
the toes of adpressed limbs (limbs firmly pressed against the sides of
the body) (Nussbaum et al. 1983; Leonard et al. 1993). Adults have a
light- to purplish-brown dorsum and the body is sprinkled with a
moderate to dense array of white to yellow flecks, concentrated on the
sides and limbs and away from the light-brown dorsal stripe. Juveniles
are black and have an olive-tan dorsal stripe that extends onto the
tail.
Recent genetic analyses recognize the Siskiyou Mountains salamander
as a distinct species from the Del Norte salamander (Plethodon
elongatus) and the Scott Bar salamander (Mead et al. 2002, 2005;
Mahoney 2004; Bury and Welsh 2005). Previously, observations of clinal
variation in color and morphometric traits from coastal populations of
Del Norte salamanders along the Klamath River to Siskiyou Mountains
salamander populations in the Seiad Valley led Bury (1973) to propose
possible intergradation between these two species, and Stebbins (1985,
2003) to demote the Siskiyou Mountains salamander to a subspecies of
Del Norte salamander.
Mead et al. (2005) described Plethodon asupak, the Scott Bar
salamander, as a new species based on analysis of molecular
(mitochondrial DNA) and morphological data from Plethodon populations
near the confluence of the Klamath and Scott Rivers in Siskiyou County,
California (Mahoney 2004; Mead et al. 2002, 2005). Molecular analysis
shows the Scott Bar salamander to be the ancestral lineage from which
the Del Norte salamander and Siskiyou Mountains salamander were derived
(Mahoney 2004; Mead et al. 2002, 2005). For the purpose of this
finding, the Service is evaluating the Scott Bar salamander as a
species separate from the Siskiyou Mountains salamander. We recognize,
however, that genetic research on these salamanders is ongoing, and the
final species' designations may be subject to the outcome of ongoing
work. This additional work may result in questions regarding the
taxonomic validity of these species and we acknowledge the potential
for those questions to be raised in the future. However, it is not
appropriate to elucidate these potential questions in this action.
The Scott Bar salamander is more robust and has a wider head and
longer limbs than either of its two most closely related sister
species, the Del Norte salamander and Siskiyou Mountains salamander
(Mead et al. 2005). It has fewer intercostal folds between adpressed
limbs (2.5 to 3.5) than either the Del Norte salamander (5 to 6) or the
Siskiyou Mountains salamander (4 to 5) and the modal number of costal
grooves (17) is one less than in the Del Norte salamander (18). The
Scott Bar salamander has a longer body relative to its tail length and
longer forelimbs and hindlimbs than the Siskiyou Mountains salamander
or Del Norte salamander. The coloration of the Scott Bar salamander is
similar to that of the Siskiyou Mountains salamander and is described
in Mead et al. (2005). Despite the morphological differences described
in Mead et al. (2005), the two species are very difficult to
distinguish in the field.
Habitat
Siskiyou Mountains salamanders and Scott Bar salamanders are found
on forested slopes where rocky soils and talus outcrops occur. Occupied
habitat for the Siskiyou Mountains salamander can range from small
isolated rock outcrops to entire hillsides (Clayton et al. 2004).
Occasionally these salamanders can be found under other types of cover
such as bark, limbs, or logs, but only during wet weather when moisture
is high and only if there are talus outcrops nearby (Nussbaum et al.
1983; Nussbaum 1974). Nussbaum (1974) characterized optimal habitat for
the Siskiyou Mountains salamander as stabilized talus in old-growth
forest stands on north-facing slopes. However, more recently
populations of both species have been found in rock outcrops in all
forest age classes and on all slope aspects (Clayton et al. 2004; USDI
2005 in litt.), as well as in managed stands (CDFG 2005). Siskiyou
Mountains salamanders have been collected in the spring during the
daytime at soil temperatures ranging from 38 to 52.3 degrees Fahrenheit
(3.5 to 11.3 degrees Celsius) and at depths ranging from 0 to 18.0
inches (0 to 45.7 centimeters) (Nussbaum et al. 1983; Nussbaum 1974).
Range and Distribution
The Siskiyou Mountains salamander's range encompasses approximately
337, 037 acres (ac) (136,500 hectares (ha)) in three counties (Jackson,
Josephine, and Siskiyou) of southwestern Oregon and northern California
(Clayton and Nauman 2005a). More specifically, this species has been
detected in the Applegate River drainage of southern Oregon south to
the Klamath River watershed of northern California. In California,
recent genetic analyses indicate the species' range is bounded to the
west by the Indian Creek drainage and to the east by the Horse Creek
drainage (see DeGross 2004; Mahoney 2004; Mead et al. 2005; Mead 2006).
It is known from sites ranging from 488 meters (1,600 feet) (Nussbaum
et al. 1983) to approximately 1,800 meters (6,000 feet) in elevation
(Clayton et al. 1999). Approximately 90 percent of the Siskiyou
Mountains salamander's range occurs on Federal lands managed under the
Northwest Forest Plan (NWFP) (USDA, USDI 1994). Within the NWFP area,
36 percent of the salamander's range occurs in reserves (Late-
Successional Reserves, Administratively Withdrawn Areas, and
Congressionally Reserved Areas) where timber harvest and other ground-
disturbing activities are severely restricted, 10 percent is within
Matrix lands generally available for timber harvest, and 44 percent
occurs in Adaptive Management Areas (AMA) where habitat management
guidelines are flexible and some timber
[[Page 23888]]
harvest is expected to occur. The remaining 10 percent of the species'
range occurs on private lands.
To date, approximately 200 Siskiyou Mountains salamander sites have
been located (Clayton and Nauman 2005a). This number represents an
unknown proportion of the total population, because surveys have not
been conducted over the species' entire range. These localities occur
primarily on Federal lands and are distributed across several NWFP land
use allocations (Clayton et al. 2004). The USDA, USDI Species Review
Panel (2002) reported that approximately 23 percent of known sites
occur on reserve lands (Late-Successional Reserves and Congressionally
Withdrawn Areas) (USDA, USDI 1994). The remaining sites occur on
Adaptive Management Areas, Matrix, and private lands.
The Scott Bar salamander is found only in Siskiyou County,
California, from just east of Seiad Valley to Scott Bar Mountain
(Clayton and Nauman 2005b). The species' range extends north and south
of the Klamath River and east and west of the Scott River and
encompasses approximately 68,438 ac (27,717 ha). Approximately 82
percent of the Scott Bar salamander's range occurs on Federal lands: 58
percent in reserves (Late-Successional Reserves) and 24 percent in
Matrix lands (USDA, USDI 1994). The remaining 18 percent of the
species' range occurs on private lands.
Clayton and Nauman (2005b) reported that fewer than ten localities
are currently known for the Scott Bar salamander, although other
locations are suspected. Based on our internal review of recent genetic
analyses (Mahoney 2004; Mahoney 2005; Mead et al. 2005; Mead 2006), 17
Scott Bar salamander localities have now been verified. Within the
presumed range of the Scott Bar salamander, numerous historical
salamander detections have been assigned to the Siskiyou Mountains
salamander. Because the two species tend not to overlap (Mead 2006), it
is reasonable to conclude that all salamander detections within what is
now known to be the range of the Scott Bar salamander are Scott Bar
salamanders. Thus, information in our files suggests that within the
range of the Scott Bar salamander there are roughly twenty known
salamander localities that are likely occupied by Scott Bar salamanders
and are additional to the 17 noted above (USDI in litt. 2006). To date,
systematic surveys have not been conducted throughout this species'
range; however, additional sites may be located in the future.
The verified localities of the Scott Bar salamander are distributed
across several watersheds that encompass the majority of the species'
known range. Of these localities, 82 percent occur on Federal lands: 35
percent in reserves (Late-Successional Reserves) and 47 percent in
Matrix lands (USDA, USDI 1994). The remaining 18 percent of the
verified localities occur on private lands. Although the sample of
known localities was not collected systematically, this distribution
suggests that the species may be well distributed within its range.
Evaluation of the range and potential population size for the
Siskiyou Mountains salamander and Scott Bar salamander is strongly
influenced by the amount and distribution of potentially suitable
habitat. The USDA, USDI Species Review Panel (2001) evaluated results
of project surveys conducted in the northern portion of the Siskiyou
Mountains salamander's range, and estimated that 3 to 14 percent of the
extent surveyed provides potentially suitable habitat. In a similar
evaluation, Timber Products Company estimated that approximately 18
percent of their surveyed lands within the range of the Scott Bar
salamander was composed of suitable talus habitat (S. Farber pers.
comm. 2006). The information from both surveys suggests that suitable
habitat for these species is patchy within these species' ranges.
Threats Analysis
Section 4 of the Act and its implementing regulations (50 CFR 424)
set forth the procedures for adding species to the Federal list of
endangered and threatened species. A species may be determined to be an
endangered or threatened species due to one or more of the five factors
described in section 4(a)(1) of the Act: (A) Present or threatened
destruction, modification, or curtailment of habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) inadequacy of
existing regulatory mechanisms; or (E) other natural or manmade factors
affecting its continued existence. In making this finding, we evaluated
whether threats to the Siskiyou Mountains salamander and Scott Bar
salamander as presented in the petition and other information available
to us may pose a concern with respect to the species' survival such
that listing under the Act may be warranted. Our evaluation of these
threats, based on information provided in the petition and available in
our files, is presented below.
A. Present or Threatened Destruction, Modification, or Curtailment of
the Species' Habitat or Range
The petition claims that logging and wildfire pose the primary
threats to Siskiyou Mountains salamander and Scott Bar salamander
habitat and populations by altering habitat structures that influence
the microclimatic conditions required by both species. The petition
states that logging and wildfire cause increases in surface
temperatures and decreases in relative humidity and soil moisture by
removing forest cover. It also states that logging has the additional
effect of compacting and realigning talus substrates. The petition
states that it is likely a substantial, yet unquantified, amount of
habitat has already been lost due to logging activities.
According to the petition, the effects of logging and wildfire on
Siskiyou Mountains and Scott Bar salamanders are based on a sequence of
relationships: the unique physiology and behavior of these species,
their dependence on moist surface conditions in order to forage and
reproduce, reduction of the occurrence of favorable surface conditions
following loss of forest cover, and loss of viability of salamander
populations inhabiting the resulting unfavorable conditions. Based on
these assertions, the petition concludes that the rate and extent of
timber harvest and fires will likely cause the two species to be
threatened or endangered due to habitat loss in the foreseeable future.
The petition and information in our files describe the
physiological and behavioral traits of Siskiyou Mountains salamanders
and Scott Bar salamanders that link them to habitats that provide moist
conditions. Both species are lungless salamanders that require moisture
in order to respire through their skin and to avoid dessication
(Nussbaum et al. 1983). These traits act to limit the time during which
the species can be active at the surface where foraging takes place
(Nussbaum et al. 1983; Feder 1983). In the warm, dry environment
characteristic of the eastern Klamath-Siskiyou Mountains, surface
conditions favorable for activity by these salamanders is limited to
relatively brief rainy periods in the spring and fall when soil
moisture and relative humidity are high and temperatures moderate
(Nussbaum et al. 1983; Clayton et al. 1999). This limitation is
reflected in survey protocols for Siskiyou Mountains salamander, which
require that surveys be restricted to periods of relative humidity
above 65 percent, air
[[Page 23889]]
temperature between 39.2 and 68 Fahrenheit (4 to 20 degrees Celsius),
soil temperature between 38.3 and 64.4 degrees Fahrenheit (3.5 to 18
degrees Celsius), and moist soil conditions; outside of these
parameters detection rates are low (Clayton et al. 1999). During the
remainder of the year, these salamanders retreat underground into
fissured rock substrates (Nussbaum et al. 1983).
Based on the relationships described above, the petition claims
that habitat conditions that further limit aboveground activity will
result in reduced abundance and viability of Siskiyou Mountains
salamander and Scott Bar salamander populations. The petition cites
Ollivier et al. (2001), who state that shortened periods of surface
conditions appropriate for feeding and breeding activities can limit
both survivorship and recruitment of these salamanders due to reduced
ability to achieve body mass and fat needed for reproduction. Based on
physiological and ecological studies of plethodontid salamanders (Feder
1983), and the association of Siskiyou Mountains salamander and Scott
Bar salamanders (and the closely related Del Norte salamander in the
Klamath province) with mature forested habitats (Nussbaum et al. 1983;
Ollivier et al. 2001; Welsh and Lind 1988; 1991; and 1995), it is
reasonable to conclude that individuals living in drier, more open
conditions may experience reduced fitness.
The petition cites Chen et al. (1993) to support the claim that
removing or reducing canopy during logging or other activities can
alter stand microclimates, which in turn would result in conditions
unsuitable for surface activity by salamanders. Information in our
files suggests that microclimatic variables such as soil moisture, fuel
moisture, relative humidity, and air temperature are sensitive to
changes in canopy, with open-canopied and unforested sites exhibiting
drier conditions, reduced humidity, and warmer air and soil
temperatures (Chen et al. 1995; Chen et al. 1999).
The petition states that rigorous pre- and post-logging studies
have not been conducted on Siskiyou Mountains salamanders or Scott Bar
salamanders. Information in our files also indicates that this type of
study has not been conducted on the similar Del Norte salamander in the
drier portions of its range. However, the petition cites several
studies from across North America (Dupuis et al. 1995; deMaynadier and
Hunter 1998; Ash 1997; Herbeck and Larsen 1999) and specific to the
Pacific Northwest (Bury and Corn 1988; Corn and Bury 1991; Raphael
1988; Welsh 1990; Welsh and Lind 1988, 1991, and 1995) that describe
impacts of logging to other plethodontid salamanders. It is important
to note that studies conducted in eastern and mid-western North America
and much of the Pacific Northwest (Grialou et al. 2000; Bury and Corn
1988; Corn and Bury 1991; Raphael 1988; Welsh 1990; and Welsh and Lind
1988, 1991, and 1995) were conducted in mesic (relatively wet) forest
types where environmental constraints (moisture, temperature) on
salamander dispersal and survival are presumably less than in the dry
eastern Klamath Mountains. In addition, most plethodontid salamander
species studied in other areas of North America occupy soil, surface
litter, and woody debris in mesic environments, whereas Siskiyou
Mountains salamanders and Scott Bar salamanders occupy talus substrates
that provide refuge from temperature extremes and dry conditions in
xeric (relatively dry) environments. Therefore, inferences drawn from
studies of other plethodontid species in mesic environments may be
limited in their applicability to Siskiyou Mountains salamander or
Scott Bar salamander populations in the dry eastern Klamath Mountains.
Studies from the mid-western and eastern United States (deMaynadier
and Hunter 1998; Ash 1997; Herbeck and Larsen 1999) and western Canada
(Dupuis et al. 1995) indicate that clear-cutting can have significant
short-term impacts to plethodontid salamander abundance, and that
second-growth stands that regenerate following clear-cutting typically
do not support the same level of abundance as do older forests. Dupuis
et al. (1995), Ash (1997), and Herbeck and Larsen (1999) reported that
plethodontid salamanders were frequently absent from 2 to 5-year-old
clear-cut forests. All of the studies that examined relative abundance
of plethodontid salamanders in different forest age classes
(deMaynadier and Hunter 1998; Herbeck and Larsen 1999; Dupuis et al.
1995) found that second-growth stands supported salamanders, albeit at
significantly lesser abundance than older forests. However, the impact
of clear-cutting on salamanders may be temporary, as one study (Ash
1997) showed that salamanders returned to clear-cut area 4 to 6 years
after cutting, and their numbers increased rapidly. Results from linear
regressions estimated that salamander numbers on clear-cut plots would
equal or exceed numbers on forested plots by 20 to 24 years after
cutting (Ash 1997).
Studies of more closely related plethodontid salamanders in the
Pacific Northwest (Corn and Bury 1991; Raphael 1988; Welsh 1990; and
Welsh and Lind 1988, 1991, and 1995) found the abundance of
plethodontid salamanders to be greater in older versus younger forests,
and most of these studies found that difference to be significant.
However, salamanders were still present in harvested areas. Raphael
(1988) reported that while Del Norte salamanders were 2 to 3 times more
abundant in adjacent old-growth forest, clear-cut areas still contained
the species. Additional information in our files (Grialou et al. 2000)
also suggests that western red-backed salamanders (Plethodon vehiculum)
occupy recent 2 to 4 year-old clear-cut areas, although at a
significantly lesser abundance than adjacent older forests. H. Welsh
and D. Ashton (in litt. 2004) obtained similar results for Del Norte
salamanders on the Six Rivers National Forest, where salamander
abundance showed a marked decline following clear-cutting, but remained
relatively stable in a lightly harvested stand. However, studies are
not consistent with respect to abundance on recently clear-cut sites.
Bury and Corn (1988) reported plethodontid salamanders to be absent in
their two clear-cut sites, but their results were equivocal because
detection rates of plethodontid salamanders were very low in all of the
habitats studied. In contrast to the above studies, Corn and Bury
(1991) found abundance of western red-backed salamanders was not
significantly different between clear-cut areas less than 10 years old
and old-growth forest.
To our knowledge, few studies exist in the peer-reviewed literature
comparing the demographics of plethodontid salamander populations in
clear-cut areas and adjacent forest. Grialou et al. (2000) studied the
abundance and demographics of salamanders, including two plethodontid
species, in mesic forests in southwestern Washington. In the year
following clear-cut harvesting, body sizes of western red-backed
salamanders were smaller (subadults and juveniles), but attained normal
size distribution by the second-year post harvest. Gravid females were
captured on clear-cut plots before and after harvest. Knapp et al.
(2003) used a randomized, replicated design to quantify plethodontid
salamander populations on harvested timberlands of the Appalachian
Mountains in Virginia and West Virginia. While salamander abundance was
less on clear-cut areas versus
[[Page 23890]]
control areas, there were no differences between cut and uncut
treatments in the proportion of gravid females or in the average number
of eggs in gravid females. Moreover, there were no differences between
cut and uncut treatments in the proportion of the sample that was
juvenile, except in one plethodontid species, which had a higher
proportion of juveniles in uncut treatments.
Because most of the aforementioned studies have been conducted on
other plethodontid species in mesic environments, the Service believes
that our evaluation should focus primarily on information collected
from Siskiyou Mountains salamander and Scott Bar salamander
populations. The petition claims that a study of habitat associations
of Siskiyou Mountains salamander by Ollivier et al. (2001) demonstrates
that the species is threatened by logging. Ollivier et al. (2001)
conducted presence/absence surveys for salamanders at 239 random
locations within the range of Siskiyou Mountains salamander (some
samples were within the range of the Scott Bar salamander), and
concluded that the species was strongly associated with characteristics
of mature forests such as closed canopies, large tree diameters, and a
mossy ground cover layer. Based on this conclusion, the petition infers
that removal of forest cover would result in habitat conditions
unsuitable for the salamanders. While the study design employed by
Ollivier et al. (2001) did not compare salamander abundance pre- and
post-harvest, their sample contained 42 precanopy plots (0-to-30-year-
old clearcuts). Subsequent to the study by Ollivier et al. (2001),
State and private biologists conducted numerous surveys and detected
Siskiyou Mountains salamanders and Scott Bar salamanders in previously
logged sites (Farber et al. 2001; CDFG 2005). These surveys followed no
sampling design and cannot be used to infer a lack of impacts caused by
logging; however, they do demonstrate that salamander populations
persist at sites that have been logged.
After reviewing data collected by Ollivier et al. (2001) and
sampling results obtained by the California Department of Fish and Game
(CDFG), H. Welsh and D. Ashton (in litt. 2004) concluded that the
viability of Siskiyou Mountains salamander populations is compromised
following clear-cutting. They based this conclusion on the high
proportion (64 percent) of juvenile and subadult animals in the sample
obtained by CDFG in non-forested habitats, and speculated that this was
an indication of a 'sink' population of dispersing individuals and low
levels of reproduction. Without further research, the effects of forest
canopy removal on the abundance and demographics of Siskiyou Mountains
salamander and Scott Bar salamander populations following logging will
remain poorly understood. Two studies examining this question are
currently in progress: One involving the Service, the Redwood Sciences
Laboratory, and Humboldt State University, and one being conducted by
Timber Products Company.
The petition also states that gaps created in the species' range by
logging could compromise the species' viability. The petition claims
that the biology of the species, narrow habitat niche, naturally
fragmented habitat, and patchy distribution limit the species' ability
to recover from disturbances. The petition cites Blaustein et al.
(1995) to support their claim that when local populations of Siskiyou
Mountains salamander are extirpated, there is little chance that the
habitat will be recolonized. The biology of the Siskiyou Mountains
salamander and the Scott Bar salamander may limit their ability to
recolonize vacant sites; however, neither the petition, nor our files,
provide information supporting the premise that logging creates gaps in
plethodontid salamander distribution by extirpating species from a
site.
The petition also states that other actions, including tractor
yarding, road construction, mining, and recreational development, have
resulted in, and will continue to result in, degradation, loss, or
fragmentation of Siskiyou Mountains salamander habitat. The petition
cites Welsh and Ollivier (1995) as suggesting that tractor yarding may
impact Siskiyou Mountains salamander habitat by compacting, breaking,
or realigning talus. Although it is reasonable to conclude that tractor
yarding may disturb talus substrates, field studies have not
demonstrated how this impacts salamander populations. The petition also
cites deMaynadier and Hunter (2000) as indicating that plethodontid
salamanders are sensitive to population fragmentation by logging roads.
Results of that study suggest that logging roads may significantly
inhibit movement and local abundance of plethodontid salamanders.
Additional information in our files (Marsh et al. 2005) suggests that
forest roads act as partial barriers to salamander movement. Road
densities within much of the ranges of the Siskiyou Mountains
salamander and Scott Bar salamander are documented to be high (USDA
1999); and may act to reduce dispersal and increase the degree of
isolation among salamander populations. This in turn may lead to
reduced gene flow and reduced long-term persistence of small, isolated
populations (Marsh et al. 2005). The extent to which this factor may be
influencing populations of Siskiyou Mountains salamanders and Scott Bar
salamanders is currently unknown.
Although the amount of habitat impacted by logging could not be
quantified, the petition contends that substantial habitat loss has
likely occurred. To support this claim, the petition cites the USDA,
USDI Species Review Panel (2001), which stated that ``cumulative
effects from past timber harvest have impacted populations on Federal
lands'' and ``from 1980 to 1990, 10 percent of habitat on the Applegate
Ranger District was clearcut.'' However, the rate and extent of timber
harvest has declined dramatically on Federal lands within the Northwest
Forest Plan area during the past 30 years (USDA, USDI 2005),
particularly on the Klamath National Forest, which comprises roughly 50
percent of the Siskiyou Mountain salamander's range and 80 percent of
the Scott Bar salamander's range. (USDA 2006). During the six-year
period from 2000 to 2005, the Klamath National Forest sold and removed
an average of 15.9 million board feet of timber annually; compared with
187.8 million board feet/year during 1985 to 1990 (inclusive), and
238.2 million board feet/year from 1979 to 1984 (USDA 2006). The
declining trend in timber harvest reduces the likelihood that a high
proportion of the salamanders' populations will be impacted by logging.
Additional information in our files suggests that extensive logging
has occurred and is likely to continue on private lands, which comprise
10 percent and 18 percent of the ranges of Siskiyou Mountains
salamander and Scott Bar salamander, respectively. For example, Timber
Products Company has informed the Service of its intent to clear-cut
harvest at several occupied Scott Bar salamander sites in 2006 as part
of a study of the species' response to timber harvest (S. Farber, pers.
comm. 2006; S. Farber, in litt. 2006). While the Service agrees that
timber harvesting has the potential to reduce habitat quality for the
Siskiyou Mountains salamander and Scott Bar salamander, Forest Service
reports (USDA, USDI 2005; USDA 2006) suggest that the rate and
magnitude of harvest on the majority of the species' ranges is not
sufficient to cause them to be threatened or endangered in the
foreseeable future.
The petition claims that fire suppression has led to an increase in
fuel loading, resulting in a change from
[[Page 23891]]
low-to high-intensity fire regimes in many forest stands within the
ranges of the Siskiyou Mountains salamander and Scott Bar salamander,
and that the risk of stand-replacing fire has increased due to forest
management practices which remove the largest, most fire resistant
trees and create young, highly combustible plantations. The petition
claims that although the response of these salamanders to fire has not
been well studied, fire has the potential to impact populations by
removing or reducing forest canopy cover. Published studies (Taylor and
Skinner 1998; Agee 1993) and Forest Service reports (USDA 1999) clearly
document that increased fuel loading and forest stand density have
increased the potential for high-intensity wildfire events within the
range of the Siskiyou Mountains salamander and Scott Bar salamander.
These high-intensity fires were much less frequent in the historical
fire regime with which these salamanders evolved. High-intensity
wildfire events, by definition, remove or significantly reduce forest
cover; consume moss, duff, and forest litter; and may sterilize surface
soil layers. The impacts of such events on salamander habitat and
populations are likely more severe than those of clear-cutting, but
have not been directly evaluated. Recent large fires within the Klamath
Province, combined with fire behavior modeling conducted by the Forest
Service, suggest a high probability of moderate- to high-intensity
wildfires within the range of the Siskiyou Mountains salamander and
Scott Bar salamander. However, fire modeling also suggests that the
level of tree mortality would be highly variable within the range of
these species (USDA 1999), resulting in a mosaic pattern of habitat
effects. Additionally, the extent to which high-intensity fire effects
would occur within habitats occupied by these salamanders is currently
unknown.
To summarize Factor A, logging, wildfire and other habitat
disturbances may impact local abundance and viability of Siskiyou
Mountains salamanders and Scott Bar salamanders by altering the
microclimate within stands that support these species, fragmenting
habitat, or otherwise reducing habitat quality. Although extensive
logging has occurred in Siskiyou Mountains salamander and Scott Bar
salamander habitat for over one hundred years, the extent of habitat
loss has not been quantified. Increased potential for stand-replacing
wildfire also places more of the species' habitat at risk. Information
in our files (e.g., Farber et al. 2001; CDFG 2005) indicates that both
Siskiyou Mountains salamanders and Scott Bar salamanders occur to some
extent in clear-cuts, second-growth stands, burned areas, and naturally
open habitats, and the demography of populations subjected to timber
harvest or fire is poorly known. This evidence suggests that while
timber harvest and wildfire may reduce habitat quality for Siskiyou
Mountains salamanders and Scott Bar salamanders, they do not result in
the extirpation of populations. Moreover, the rate and extent of timber
harvest has declined dramatically on Federal lands within the Northwest
Forest Plan area, particularly the salamanders' ranges on the Klamath
National Forest, during the past 30 years (USDA, USDI 2005; USDA 2006).
Based on current Forest Service policies, we anticipate that the rate
of timber harvest will remain at roughly present levels in the
foreseeable future. Although it is reasonable to assume that high-
intensity wildfire may have a negative impact on salamander habitat and
populations, we currently have no information and the petition provided
no information to support a determination that fire is a substantial
risk. We therefore find that the petition and other information in our
files do not present substantial information that the continued
existence of these species are threatened by the present or threatened
destruction, modification, or curtailment of the species' habitat or
range in the foreseeable future.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
The petition and our files did not provide any information
pertaining to Factor B. Information in our files indicates that tissue
samples have been, and will likely continue to be, collected from
individual salamanders in the field. However, methods used to collect
genetic material for analysis are not expected to cause harm to the
salamanders.
C. Disease or Predation
Neither the petition nor information in our files present any
information pertaining to Factor C.
D. Inadequacy of Existing Regulatory Mechanisms
Federal lands: The petition cites the USDA, USDI Species Review
Panel (2001) to demonstrate that approximately 80 percent of the
Siskiyou Mountains salamanders' range occurs on Federal lands managed
by the Rogue-Siskiyou and Klamath National Forests and the Medford
District of the Bureau of Land Management. Thirty-nine percent of the
species' range occurs within protected land designations under the
Northwest Forest Plan (NWFP) (USDA, USDI Species Review Panel 2001).
Additionally, the petition cites Clayton et al. (2002 as cited in USDA,
USDI 2004) to demonstrate that less than 10 percent of suspected high-
quality habitat occurs in reserves. The petition thus concludes that
the majority of the species' ranges and high-quality habitat occurs on
Federal lands available for timber harvest and other activities. The
petition cites the USDA, USDI Species Review Panel (2001) to suggest
that specific protections on non-reserve land allocations will likely
be required to ensure persistence of the species.
The petition claims that the Siskiyou Mountains salamander formerly
received substantial protection on Federal lands from the Survey and
Manage Program (USDA, USDI 1994). The petition claims that this program
was abolished with the Record of Decision entitled ``To Remove or
Modify the Survey and Manage Mitigation Measures Standards and
Guidelines in Forest Service and Bureau of Land Management Planning
Documents Within the Range of the Northern Spotted Owl'' in March 2004
(March 2004 ROD). The Final Supplemental Environmental Impact Statement
for the March 2004 ROD addressed potential mitigation, including
sensitive species programs, for species affected by the removal of the
Survey and Manage Program. However, the petition claims that the
sensitive species programs provide substantially less protection by
failing to require surveys and making mitigation optional. The petition
cites a USDA, USDI (2004) statement that the elimination of the Survey
and Manage Program may result in gaps in the Siskiyou Mountains
salamander's range.
According to the petition, in the absence of the Survey and Manage
Program, management of the Siskiyou Mountains salamander would be
governed under/by the standards and guidelines of the NWFP. According
to the petition, 78 percent of the known sites north of the Siskiyou
Crest occur in the Applegate AMA. Under the NWFP, AMAs were created to
``encourage the development and testing of technical and social
approaches to achieving desired ecological, economic, and other social
objectives,'' with each AMA having a management plan (USDA, USDI 1994).
Because an agency plan for the Applegate AMA has not been produced, and
standards and guidelines for activities in AMAs are more flexible than
in other land-use allocations, the petition claims that
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existing guidelines for the Siskiyou Mountains salamander in the
Applegate AMA would result in limited protection for the species.
However, the petitioners provided no documentation to suggest that
Federal actions in the AMA are having an effect on the salamanders.
The status of the Survey and Manage program is in flux. In January
2006, the United States District Court, Western District of Washington
in Northwest Ecosystem Alliance, et al., v. Mark E. Rey, et al., Case
2:04-CV-00844-MJP, ordered the March 2004 ROD set aside for failure to
comply with the National Environmental Policy Act. With this, the court
reinstated the 2001 Survey and Manage ROD as it stood on March 2004.
The Survey and Manage Program is therefore the current regulatory
mechanism in place for the United States Forest Service and Bureau of
Land Management lands that the Siskiyou Mountains salamander occupies.
Under these provisions, all currently known and future sites south of
the Siskiyou Crest will be managed to maintain species persistence and
surveys will be conducted prior to habitat-disturbing activities. North
of the Siskiyou Crest, high-priority sites will be identified and
managed to provide a reasonable assurance of species persistence.
The Scott Bar salamander is not specifically addressed by name in
the Survey and Manage ROD protections. However, the Klamath National
Forest has formally stated that Survey and Manage protections for
Siskiyou Mountains salamander also extend to the Scott Bar salamander,
since they cannot be easily distinguished in the field (M. Boland, in
litt. 2006). Thus, protections for the Scott Bar salamander on Federal
lands are in place.
According to the court's order, the defendants indicated that they
plan to propose a supplement to the 2004 Final Supplemental
Environmental Impact Statement to address the deficiencies identified
by the court, followed by a new ROD on or before March 30, 2007. It is
unknown what protections will be provided the Siskiyou Mountains
salamander in future decisions. If existing Federal regulations are
modified in the future, the adequacy of these regulations to protect
the Siskiyou Mountains salamander and Scott Bar salamander should be
evaluated at that time.
State Regulations:
The State of Oregon provides no regulatory protections for the
Siskiyou Mountains salamander on private lands (approximately 10
percent of the species' range). In California, the Siskiyou Mountains
salamander is listed as a threatened species and receives substantial
protection pursuant to the California Endangered Species Act (CESA).
These protections include pre-project surveys and prohibitions on
timber harvest in established buffers around suitable habitat. In 2005,
CDFG submitted a petition to the California Fish and Game Commission to
delist the Siskiyou Mountains salamander. Because of CDFG's delisting
proposal, the petitioners claim that the protections provided by CESA
should not be considered to provide firm regulatory protection for the
species. The final determination on whether to delist the Siskiyou
Mountains salamander is expected to be made at the Fish and Game
Commission's January 31, 2007 meeting. If existing State regulations
are modified in the future, the adequacy of these regulations to
protect the Siskiyou Mountains salamander should be evaluated at that
time. Unless and until the Siskiyou Mountains salamander is delisted as
a threatened species, it remains protected pursuant to the CESA.
In July 2005, the Scott Bar salamander appeared on the CDFG's
Special Animals List (CDFG 2006). The CDFG describes the Scott Bar
salamander as a ``newly discovered species from what was part of the
range of Plethodon stormi.'' Currently, the Scott Bar salamander does
not have any special management status (rare, threatened, or endangered
species; fully protected species; or species of special concern) in
California, and thus receives no special management considerations or
additional protections on approximately 18 percent of its range.
Adequate regulatory mechanisms are lacking on approximately 10
percent of the Siskiyou Mountains salamander's range and 18 percent of
the Scott Bar salamander's range. However, research suggests that
populations of plethodontid salamanders persist following timber
harvest. Therefore, the Service believes that the lack of regulatory
protections on a limited proportion of the species' ranges does not
likely pose a threat to the species in the foreseeable future.
To summarize Factor D, existing Federal regulations currently
provide substantial protection for the Siskiyou Mountains salamander
and Scott Bar salamander through the Survey and Manage program. Thus,
the fact that significant portions of the Siskiyou Mountains salamander
and Scott Bar salamander ranges include Federal lands available for
timber harvest (Matrix and AMA) does not in itself constitute a threat
to the species.
Current California regulations provide substantial protection for
the Siskiyou Mountains salamander on private lands. Existing California
regulations provide no special management protections for the Scott Bar
salamander on private lands. Likewise, Oregon provides no regulatory
protections for Siskiyou Mountains salamanders on private lands.
However, private lands comprise only 18 percent of the Scott Bar
salamanders' range and only 10 percent of the Siskiyou Mountains
salamanders' range in Oregon. Thus, substantial protections are
provided to both species across the majority of their ranges. Although
the Forest Service and Bureau of Land Management have indicated they
plan to develop a supplement to their March 2004 ROD addressing
deficiencies in that document identified by the court, and the State of
California is currently evaluating a petition to delist the Siskiyou
Mountains salamander, no decisions regarding these actions have yet
been reached that would effect existing regulatory mechanisms. Thus,
the Service considers the current Federal and State regulations
adequate for both salamander species. If these regulations are modified
in the future, the adequacy of these regulations to protect the
Siskiyou Mountains salamander and the Scott Bar salamander should be
evaluated at that time.
Because Federal and State of California regulations are currently
in effect and offer protection for the Siskiyou Mountains salamander
and Scott Bar salamander over the majority of the species' ranges, the
petition and other information in our files does not present
substantial information that these species are threatened at this time
by the inadequacy of existing regulatory mechanisms across all or a
significant portion of their ranges.
E. Other Natural or Manmade Factors Affecting the Species' Continued
Existence
The petition states that ``an increasing consensus has developed
that we are and will continue to experience global warming.'' The
petition cites Feder (1983) and Ollivier et al. (2001) to propose that
the unique physiology and requirement of moist conditions for foraging
and breeding activity make the Siskiyou Mountains salamander and Scott
Bar salamander particularly sensitive to variations in climate. Thus,
the petition suggests that the expected change in climate over time is
likely to influence the species distribution and ability to find
suitable habitat. The petition also claims that warmer temperatures may
shorten the window
[[Page 23893]]
in which the species is able to forage and reproduce. According to the
petition, warmer temperatures may also negatively affect habitat by
increasing the severity and intensity of forest fires, resulting in
loss of forest canopy. While providing information on climate change
the petition did not provide information beyond speculation regarding
the effects of microhabitat changes that may be brought about by
regional climate change.
The petition also cites USDA, USDI (2004) to demonstrate that, due
to limited habitat and the known existence of only three localities,
the Scott Bar salamander is at risk of extinction due to genetic or
demographic stochasticity, regardless of management direction. However,
information in our files suggests that the number of known localities
and existing habitat within the range of the Scott Bar salamander is
considerably larger than that considered in USDA, USDI (2004). The
existence of 37 currently known sites decreases the potential for
extinction caused by stochastic events, although the species' range is
still considered small and restricted. Stochastic events pose less of a
threat to the Siskiyou Mountains salamander due to the greater number
of known localities and relatively larger range.
To summarize factor E, because foraging and breeding activities are
dependent upon cool, moist conditions, these salamanders may be
susceptible to alterations in microclimate resulting from projected
climate change. However, neither the petition nor other information in
our files provides anything more than speculation on the type,
magnitude, or temporal effects of microhabitat changes that may be
brought about by regional climate change. Finally, the petitioners
assert that the Scott Bar salamander is at risk because its small,
restricted range makes this species vulnerable to extinction as a
result of stochastic events. Although the range of the Scott Bar
salamander is considered restricted, the number of currently known
populations is considerably greater than stated in the petition.
Additionally, a considerable amount of suitable habitat capable of
supporting the Scott Bar salamander has yet to be surveyed. Thus, the
Service believes that the Scott Bar salamander may be less susceptible
to stochastic events than the petition claims. Therefore, we find that
the petition does not contain substantial information suggesting that
other natural or manmade factors may be a factor that threatens either
species.
Finding
We evaluated each of the five listing factors individually, and
because the threats to the Siskiyou Mountains salamander and Scott Bar
salamander are not mutually exclusive, we also evaluated the collective
effect of these threats. The petition focused primarily on two listing
factors: the Present or Threatened Destruction, Modification, or
Curtailment of the Species' Habitat or Range and the Inadequacy of
Existing Regulatory Mechanisms. More specifically, the petition and
information in our files suggest that logging and fire pose the most
likely threats to Siskiyou Mountains salamander and Scott Bar
salamander habitat and populations, because the majority of the
species' ranges occur on lands available for timber harvest or lands
susceptible to stand-replacing wildfires. Synergistically, timber
harvest and fire have the potential to impact extensive amounts of
habitat and a large number of discrete populations. The Siskiyou
Mountains salamander's numerous distinct localities and occurrence both
north and south of the Siskiyou Crest likely increase the resilience of
this species to logging and wildfire. Additionally, current Federal and
State of California regulations provide substantial protection for the
Siskiyou Mountains salamander on both Federal and private lands.
Therefore, the Service believes that the Siskiyou Mountains
salamander's numerous localities and existing Federal and State of
California regulations ameliorate, to some degree, the potential
synergistic effects to this species.
Synergistic effects are of greater concern for the Scott Bar
salamander. This species has a restricted range and substantially fewer
known localities. Information in our files also indicates that portions
of the species' range are at high risk of fire (USDA 1999), and
clearcut harvesting is scheduled to occur at known sites. However,
plethodontid salamander populations have been shown to persist where
logging occurs and the Survey and Manage protections currently afforded
this species on the majority (82 percent) of its range act to minimize
the risk of habitat loss due to timber harvest. Additionally, fire
effects analysis within the range of the Scott Bar salamander indicate
that if a wildfire were to occur, the area would have mixed levels of
stand mortality, resulting in a mosaic pattern of habitat effects (USDA
1999). Therefore, the Service finds that the synergistic effects of
fire and logging do not threaten the continued existence of the Scott
Bar salamander in the foreseeable future.
We have reviewed the petition and other information available in
our files. Based on this review, we find that the petition and
information in our files do not present substantial information
suggesting that listing the Siskiyou Mountains salamander or Scott Bar
salamander as threatened or endangered may be warranted at this time.
References Cited
A complete list of all references cited herein is available, upon
request, from the Yreka Fish and Wildlife Office (see ADDRESSES
section).
Author
The primary authors of this notice are staff of Yreka Fish and
Wildlife Office, U.S. Fish and Wildlife Service, 1829 S. Oregon Street,
Yreka, California 96097.
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: April 17, 2006.
Kenneth Stansell,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. E6-5977 Filed 4-24-06; 8:45 am]
BILLING CODE 4310-55-P